Prominent atrial wave and diastasis deflection in the radionuclide diastolic volume curve during exercise - Sensitive marker for coronary artery disease

It is well-known that many patients with coronary artery disease have reduced left ventricular diastolic distensibility with normal systolic function. However, researchers have to date focused on the diastolic rapid filling phase of the radionuclide volume curve in ischemic patients, paying less attention to the ensuing left ventricular filling associated with passive filling ('diastasis') and atrial contraction ('A' wave). We analyzed the radionuclide volume curves of 27 consecutive patients suspected ischemic heart disease, who manifested normal systolic function at rest and during exercise,as assessed by multigated equilibrium technetium-99m radionuclide cineangiography. For all patients, the amplitute of the maximal 'A' deflection relative to the peak of the diastolic curve (presented as percentage units) was calculated manually from the radionuclide left ventricular volume curves obtained at rest and during exercise. Twenty patients (Group I) had transient perfusion defects on thallium scintigraphy (treadmill), and 7 (Group II) did not. Patients in Group I manifested prominent 'A'-deflections during exercise, with arise of 120 ± 43% (mean ± S.D.) from rest to exercise, whereas the patients in Group 11 had only 34 ± 11% (mean ± S.D.) rise in 'A' wave amplitude during exercise (P = 0.0001). We conclude that the appearance of a prominent 'A' deflection in the radionuclide left ventricular volume curve during exercise might be a sensitive marker of myocardial ischemia.